Cooling tunnel for hot sheet or strip



Sept 19, 1961 F. U. HILL ET A1. 3,000,109

COOLING TUNNEL FOR HOT SHEET OR STRIP 4 Sheets-Sheet l Filed D90. 5l,1957 INVENTORS Fkn/vc/s U. HILL BY MOPrQNLS/MGN L7M QQLWQM@y Sept 191961 F. u. HILL ETAL 3,000,109

COOLING TUNNEL FOR HOT SHEET OR STRIP Filed Dec. 5l. 1957 4Shaecrs-Sheei'l 2 Arrows/Ey Sept. 19, 1961 F. U. HILL ErAL 3,000,109

COOLING TUNNEL FOR HOT SHEET OR STRIP Filed Dec. 51. 1957 4 sheets-sheet-5 MMMMIMMHMM Mmm ' INVENTORS 5M vc/5' d //LL BY Makro/v S/MoN ,4rroRA/E y Sept. 19, F. U HILL ETAL COOLING TUNNEL FOR HOT SHEET OR STRIPFiled Deo. 3l, 1957 4 Sheecs-Sheecl 4 By Mom-on L. /Mo/v d@ Mm( ATron/va y United States Patent Ohio Filed Dee. 31, 1957, Ser. No.706,489 1 Claim. (Cl. 34-156) Our invention relates to apparatus forcooling hot strip or sheet and more particularly is an improvement incooling tunnels for rapidly cooling hot strip or sheet metal, glass orplastic while it is passing through the apparatus.

One of the objects of 'this invention is an apparatus of the above namedcharacter by the use of which production of sheet or strip steel may beincreased materially and may be accomplished more economically than withapparatus and methods heretofore known.

Another object of the invention is to cool annealed sheet or strip athigher speeds or rates of shorter runs than heretofore.

Another object of the invention is to conserve space by providing anapparatus which will satisfactorily cool hot sheet or strip by passingthe same through a cooling tunnel in one direction in a stream of acooling medium passing through the tunnel and around the sheet or stripin a direction opposite to that of the movement of the sheet or strip.

Another object of the invention is to eliminate the necessity forcooling sheet or strip at room temperatures which methods necessarilyrequire a longer run for the sheet or strip and many times the oor spaceas contrasted to that which is utilized in practicing our invention.

A further object resides in the metallurgical benefits obtainablethrough the ability to control the cooling of the sheet or strip.

A still further and important object of the invention is a coolingapparatus of the class described having a dow acceierating nozzle at thecoolant input end of the tunnel and a jet diffuser at its discharge endto recover the energy of the coolant stream emerging from the tunnel.

Another object of the invention is to permit the installation of such anapparatus for effective and eicient operation within a limited buildingfloor area and at a high rate of speed as distinguished from the slowerand less efficient methods now in use of which we are aware.

Other objects and advantages of this invention will become more apparentas the following description of an embodiment thereof progresses,reference being made to the accompanying drawing in which like referencecharacters are employed to designate like parts throughout the same.

in the drawings:

FIGURE 1 is a front elevation of an apparatus embodying our inventionshowing the manner in which the hot sheet or strip is fed through thetunnel in a direction opposite to that of a ow through the tunnel of acoolant, such as air;

FIGURE 2 is a top plan view of the apparatus shown in FIGURE 1;

FIGURE 3 is a side elevation of one end of the apparatus as indicated byline 3-3 of FIGURE l and looking in the direction toward the exhaustmanifold;

FIGURE 4 is a. top plan view of an apparatus illustrating a modied formof the invention in which the coolant enters the tunnel from itsopposite ends and is discharged through diifusers into a common exhaustintermediate the tunnel ends;

FIGURE 5 is a section on line 5-5 of FIGURE 6; and

FIGURE 6 is a side elevation of the apparatus shown in FIGURES 4 and 5.

ice

Heretofore, so far as we are aware, the cooling of hot strip or sheetannealed steel has been accomplished by different methods, that is, bywater spraying, roll cooling or water baths, or by passing the striplengthwise over rollers for relatively long runs with the sheet orstrip'l exposed to the room air which will slowly cool the same, but oneof the great disadvantages is that by such method of room air cooling,ythe sheet or strip must be moved linearly over considerably longdistances to adequately cool the same for coiling. Under such practice,a lot of space was required and, in many cases, new buildings oradditions to buildings were necessary to provide the adequate run spacefor the sheet or strip during the coolingV phase. As has been pointedout above, it is an important object of this invention to provide meanswhereby the hot sheet or strip may be more quickly and adequately cooledby air in a relatively short linear run, thus making it unnecessary toprovide buildings of a length sutiicient to coil the strip under the oldmethods.

In carrying out the present invention, we have illustrated in thedrawings two embodiments thereof as applied in use for rapidly coolingmetal, glass or plastic in sheet or strip form, and will now proceed todescribe .the same and its operation, referring first to FIGURES l, 2and 3, which illustrate one form of the invention.

We have found that by causing the hot strip of sheet to travel in onedirection through an air tunnel, and in spaced relation thereto, and atthe same time to cause a coolant, such `as air, to be forced at highvelocity through the tunnel and around the hot sheet or strip and movingin a direction opposed to that of the direction of the sheet or strip,that the principal objects of this invention are easily attained, thatis, the relatively short distance the hot sheet or strip will have totravel, the consequent saving of linear travel of the hot sheet or stripin the tunnel and the consequent lack of requirement of a relativelylong tunnel, as contrasted to previous methods, the resultant materialincrease in productive capacity, the utilization of a high velocitycooling air stream surrounding the sheet in the tunnel and injected intothe tunnel through a ow accelerating nozzle, together with a jetdiffusing means located at the discharge end of the tunnel whereby theenergy of the cooling air stream may be recovered as the heated air iscommunicated to the discharge or outlet manifold of the apparatus.

More specilically, the embodiment illustrated in FIG- URES 1-3,inclusive, includes a means for supplying a cooling air stream at highvelocity which is indicated generally by the supply manifold 1, adischarge manifold 2 and a connecting tunnel 3 whereby a cooling airstream from the supply manifold may be directed through the tunnel andthence outwardly to the exhaust manifold, as will be described ingreater particular hereinafter.

The hot strip or sheet to be cooled is indicated generally at 4 in FIG.1 and, as indicated by the arrows, is caused to move from left to rightthrough the two manifolds and the cooling tunnel, the same beingsupported between suitable rollers S mounted in the supply manifold andalso between the rollers 5 mounted in the discharge manifold.

The supply unit or manifold 1 comprises a housing in which is mounted anelectric motor 6 for driving the impeller 7, there'being a guard 8disposed over the motor and having an open mesh construction whereby airmay be admit-ted through the guard to be driven by the impeller 7downwardly through the housing 9 and into the twin manifold sections 10and 11, as indicated by the arrows in the input unit to the right ofFIG. l. Within the manifold 1 is provided an accelerating nozzleindicated generally at 12, which communicates the air ow under thepressure of the impeller into the tunnel 3 at ,its right hand end athigh velocity in FIG. l, through column to pass upwardly through theducts of manifold sections 16 and 17 and into the discharge warmed airoutlet 18 where the column will be forced outwardly through thedischarge duct 19 by means of the fan 20 operated by the electric motor21.

It will be noted that the tunnel is of generally rectangular shape incross section, being wide enough to accommodate the sheet or strip forfree linear movement therealong, as indicated in FIG. 3, and being ofrelatively short height in cross section as seen in FIG. 3, but aiordingan air ow space or air envelope through which the sheet or strip mayhave unrestricted passage. Access doors 22 and 23 may be provided alongthe sides of the tunnel at desired points. The tunnel 3 includes upperand lower walls 24 and 25, respectively, which are in close proximity tothe top sheet or strip 4 passing therebetween but which are spaced fromthe sheet or strip or from each other suiciently to provide adequateflow of high velocity cooling air substantially all around the sheet asit passes through the tunnel.

Partitions or walls 30 and 31 are provided vertically in the manifolds 1and 2, respectively, and each has a mouth or opening 32 extending towardthe rollers 5 and to provide for the passage of the sheet or strip 4therethrough. Flanged portions 33 are provided to lie close to theperiphery of the rollers 5 and '5' so as to supply a partial sealtherebetween thus effectively directing the cool air flow from thesupply manifold through the accelerating nozzle 12, the tunnel 3surrounding the moving Strip 4, the jet d iiuser 14 and finally out ofand through the discharge manifold.

It is desirable that there be a slight sag in the tunnel, as at 40,between the accelerating nozzle and the jet diffuser to accommodate thenatural sag of the sheet or strip in the tunnel since in this area thereare no supporting rollers provided.

Referring now more particularly to FIGS. 4, 5 and 6, we will describethe embodiment illustrated therein. In this 'form of the invention, wealso employ means for accelerating the movement of the coolant torelatively high velocity as the same enters and passes through thetunnel and around the sheet or strip toward the discharge end of thetunnel. Furthermore, we employ a jet diffuser at the discharge end ofthe tunnel.

In the present embodiment, however, We employ a cooling tunnelconsisting of a pair of aligned tunnel units each of which extendsoutwardly from opposite sides of a coolant discharge manifold andforming with the manifold a continuous passage or tunnel for the sheetor strip to be cooled.

We, therefore, provide the two tunnel units 50 and 51 supported in asubstantially horizontal position but presenting a slight sag from theouter ends of the respective units inwardly toward the dischargemanifold to accommodate the natural sag of the sheet or strip passingtherethrough. An accelerating nozzle is secured at each end of theassembled tunnel as at l52 and 53, and each nozzle has connection with asource of coolant such as air under pressure from a blower (not shown).

'I'he inner ends of the tunnel units 50 and 51 are each provided with ajet diffuser as at 54 and 55, both having connection at their enlargedends with the coolant discharge manifold or outlet at 56.

The manifold 56 is connected with a chamber or housing 57 within whichmay be mounted an impeller (not shown) for forcing the coolantdischarged from the tunnel upwardly and outwardly through the flue 58.This hue may have communication with a duct or the like to convey theused coolant out of the build'mg housing the apparatus.

lIn this form of the invention, it will be noted that the coolant isintroduced into the tunnel at its opposite ends through the acceleratingnozzles 52 and 53, and consequently travels through the tunnel from itsend portions, enveloping the sheet or strip passing through the tunnel,to be discharged at the intermediate section through the respective jetdiffusers 54 and 55 and into the discharge manifold 56. lThus, while thehot sheet or strip to be cooled enters the tunnel, say from the leftside of FIG. 6, as indicated by the direction arrow to the left of theligure, and passes `through the tunnel, it will be enveloped in the highvelocity coolant stream moving in the same direction as the sheet orstrip for that portion of the latters travel from that end of the tunnelthrough the jet diffuser 54. As the sheet or strip continues through thejet diffuser '55, the tunnel section 51 and out through the acceleratingnozzle 53, it will be moving in an envelope of high velocity coolanttraveling in a direction opposed Vto that of the sheet or strip.

iBy such an apparatus, we have provided means which will effectively andquickly cool hot sheet or strip along a linear path of greatly reducedlength as contrasted to present day cooling apparatus of which we areaware. By the use of accelerating nozzles at the coolant input, weobtain a high velocity coolant stream through the tunnel while the jetdiiusers employed recover much o-f the energy of the coolant streamemerging from the tunnel.

Various changes may be made in the details of construction andarrangement of parts of the invention without departing from the spiritthereof or the scope of the appended claim.

We claim:

In an apparatus for rapidly cooling longitudinally moving hot metalstrip or sheet, an elongate straight through cooling tunnel open at itsopposite ends to the outside atmosphere and through which the strip orsheet to be cooled is passed in one direction, said tunnel including apair of axially aligned sections forming a continuous tunnel throughwhich a cooling lluid is moved at high velocity, means for injecting asheet or strip enveloping cooling fluid into both ends of the axiallyaligned tunnel sections, iiuid velocity accelerating means carried bythe opposite ends of said tunnel for injecting the cooling uid at highvelocity into the respective tunnel sections, opposed jet diffusingmeans intermediate the tunnel ends for discharging the spent coolingfluid from each of the tunnel sections, said opposed jet diifusing meansincreasing in cross sectional area toward an exhaust manifold andsubstantially equally on both sides of the longitudinal axis through thetunnel, an exhaust manifold communicating with the respective diffusingmeans, and a spent cooling fluid discharge flue communicating with saidmanifold.

References Cited in the le of this patent UNITED STATES PATENTS 92,210Richardson July 6, 1869 463,266 Allis Nov. 17, 1891 1,847,915 BaileyMar, 1, 193 2,012,115 Woodruff Aug. 20, 1935 2,346,764 Kratz Apr. .18,1944 2,542,064 -Tilden Feb. 20, 1951 2,645,031 Edwards July 14, 19532,775,046 Kabelitz Dec. 25, 1956 2,783,546 Armstrong Mar. 5, 1957

